Electrical connectors for telemetering drill strings

ABSTRACT

An improvement in the arrangement of electrical connectors positioned in the joints of drill string pipe sections which are joined together to form a telemetering drill string. The improved electrical connectors are positioned in the pipe joints and connect insulated segments of an electrical connector positioned in the drill string pipe sections.

United States Patent Oertle ELECTRICAL CONNECTORS FOR TELEMETERING DRILLSTRINGS 3 l70 l37 2/1965 Brandt 340/18 LD [75] Inventor: Don H. Oertle,Ponca C11)" Okla. Prinmry E \,aml.ner Roy Lake [73] Assignee:Continental Oil Company. Ponca Assislum Eraminer-DeWalden W. Jones City,Okla. Attorney, Agent. or FirmF. Lindsey Scott [22] Filed: Jan. 25, 1974[21] Appl. No.: 436,551

1 1 ABSTRACT [52] US. Cl 339/16 R; 174/47; 339/60 R;

339/94 R; 340/18 LD An improvement in the arrangement of electrical con-[51] Int. Cl. H01r 3/04 n r p ition in he joints of rill string pipesec- [58] Field of Sear h 339/16 R, 16 C, 16 RC, tions which are joinedtogether to form a telemetering 339/60 R, 60 M, 94 R, 94 M; 340/18 L1);drill string. The improved electrical connectors are 174/47, 104positioned in the pipe joints and connect insulated segments of anelectrical connector positioned in the [56] References Cited drillstring pipe sections.

UNITED STATES PATENTS 452.506 5/1891 Klumpp, Jr. 339/16 R X 10 Claims, 6Drawing Figures 34- z4- 3e 2e 3o |o &2 i 52 48 :2: I e

ELECTRICAL CONNECTORS FOR TELEMETERING DRILL STRINGS This inventionrelates to transmitting an electrical signal along a drill string whileit is in the borehole of a well. More particularly, the inventionrelates to an information telemetering drill string which can beassembled and used without special drill string manufacturing and/ordrilling techniques or precautions.

The desirability of transmitting an electrical signal along a drillstring was recognized over years ago. Numerous systems have beenproposed. Typical earlier proposals required specially constructed drillpipe sections such as those described in U.S. Pat. No. 2.178.931 orrequired internally mounted electrical connector arrangements that causea significant reduction in the internal diameter of the drill pipe suchas those described in U.S. Pat. Nos. 2.301.783 and 3,253,245.

U.S. Pat. No. 2,53 l .120 describes a system for transmitting electricalpower along a drill string to drive an electrical drilling motor. Ituses ring and contact-pin electrical connectors which are mounted withinmating portions of the pipe joints and avoids the need for speciallyconstructed drill pipe sections or restrictions of the drilling fluidpassageway. The ring and contact pin arrangement is disadvantageous withrespect to transmitting an electrical information signal. In aninformation signal connectorintroduced noise may mask the information orprovide misleading information.

In the procedures usually employed for assembling and disassembling orround tripping" a drill string, the mating portions of the pipe jointsbecome coated with fluids having varying degrees of electricalconductivity. Any electrical connectors which are mounted in suchportions of the drill pipe joints are almost inevitably smeared withvarious non-conductive fluids such as oils, greases. pipe threadlubricant and the like. An information conveying electrical signal tendsto become noisy and relatively severely attenuated when it is conveyedacross a plurality of pipe joints containing electrical connectors inwhich the contacting elements are rings and contact-pins. In such asituation each metalto-metal contact area is relatively small and theeffective contact resistance tends to vary widely due to the presence ofdiffering amounts of nonconductive fluids that tend to remain betweenthe contactpins and rings.

U.S. Pat. No. 3,696,332 describes an arrangement of electricalconnectors positioned in drill pipe joints. The electrical connectorsare rings positioned in the shoulders of the drill pipe joints. Themating surfaces appear to be flat and rely primarily on the wipingaction as the two rings are joined during make-up of the pipe joint toclean the surfaces of the rings and secure a good electrical contacttherebetween. Apparently, the means for sealing fluids inside andoutside the drill pipe away from the rings consists of a metal-to-metalseal consisting essentially of sealingly mating shoulders on the pipesections.

One disadvantage of such an arrangement is that it is difficult toobtain sealing mating in the shoulders when more than one surface mustbe precisely machined. For instance it is difficult to get both theinner and the outer shoulders to mate closely enough to achieve acomplete seal in all instances. As is obvious to those skilled in theart it is undesirable that the drill pipe require such precise machiningsince such machining increases the expense. is vulnerable to damage inthe field and the like. Additionally, the contacting faces of the ringstend to become smooth and flat and minute particles wedged therebetweentend to have a large effect on the conductivity across the metalto-metaljunction. It is also difficult to remove all contaminants between therings by the wiping action when large amounts of viscous contaminantsare present during the joint make'up.

It is an objective of the present invention to provide an improvedarrangement of electrical connectors positioned in the drill string pipejoints.

The objective of the present invention is achieved in a telemeteringdrill string in which segments of an insulated electrical conductor arejoined by electrical connectors in mating portions of drill string pipejoints that contain mating shoulders by an improvement in thearrangement of the electrical connectors comprising: (a) positioning ineach drill string pipe joint, the joints comprising the union of a maleand a female threaded member; a first and a second ring-shapedsubstantially full-circle contact-making ring. the first ring beingpositioned in the male member in a groove between the shoulder and thethreaded portion of the member, the second ring being positioned in thefemale member in a cavity between the shoulder and the threaded portionof the member. each of the rings being in electrical contact with asegment of the insulated electrical conductor, electrically insulatedfrom the member in which it is positioned and having a contact surfaceforming an angle from 15 to 65 with the longitudinal axis of the drillstring; (b) a first and second sealing means positioned in each drillstring pipe joint to sealingly separate the rings from fluids inside andoutside the drill string. the first sealing means being positionedbetween the rings and the outer diameter of the drill string pipe andthe second sealing means being positioned between the rings and thethreaded portion of the joint; and (c) resilient biasing meansoperatively associated with at least one of the rings to urge the ringtoward a position from which it is displaced by the adjacentcontact-making ring as the members are screwed together.

FIG. 1 shows an embodiment of the improved connector of the presentinvention in a drill string pipe joint.

FIG. 2 is a sectional view ofa portion of a similar drill string pipejoint showing a further embodiment of the improvement of the presentinvention.

FIG. 3 is a sectional view ofa portion of a similar drill string pipejoint showing a further embodiment of the present invention.

FIG. 4 is a sectional view of a portion of a similar drill pipe stringjoint showing a further embodiment of the improvement of the presentinvention.

FIG. 5 is a sectional view of a portion of a similar drill string pipejoint showing a further embodiment of the improvement of the presentinvention.

FIG. 6 is a sectional view ofa portion of a similar drill string pipejoint showing a further embodiment of the improvement of the presentinvention.

In FIG. 1 a drill string pipe joint 10 comprising the union of a malemember 12 and a female member 14 is shown. The male member includesthreads 16 and the female member includes threads 18. The drill stringpipe sections joined include segments of an insulated electricalconductor 20. The insulated electrical conductors are positioned inpassageways .22 in the drill string pipe sections and are connected toelectrical connectors at each end of the drill string pipesections. Themale member has positioned thereon a shoulder 24 and the female memberhas positioned thereon a shoulder 26. The electrical connectors 28comprise a first ring-shaped. substantially full-circle contact-makingring 30 positioned on the male member and a second ring-shaped.substantially full-circle contact-making ring 32 positioned on thefemale member. The first ring is positioned in a groove 34 between theshoulder and the threads on the male member. The second ring ispositioned in a cavity 36 between the shouldler and the threads on thefemale member. The first ring is insulated from the male member byinsulation 38 positioned in the gr'oove"between'the ring and the malemember. The second ring is insulated from the female member byinsulation 40 positioned in the cavity between the ring and the femalemember. The rings are each in contact with a segment of the insulatedelectrical conductor and each ring includes a contact surface whichforms an angle from about to about 65 with the longitudinal axis 42 ofthe drill string. The insulation 38 and is of a resilient nature andtends to urge the rings into a position from which they are displaced asthe pipe joint members are screwed together. The insulation 38positioned on the male member is desirably more resilient than theinsulation 40 used on the female member. The electrical connectorsinclude means for sealingly separating the rings from fluids 44 outsidethe drill pipe and from fluids 46 inside the drill pipe. The sealingmeans include a first sealing means 48 and a second sealing means 50. Inthe embodiment shown in FIG. 1, the first sealing means comprises asealingly mating junction of shoulders 24 and 26. The second sealingmeans is a generally ring-shaped, substantially full-circle resilientmember shown as an O- ring 52 positioned in a groove 54 on the malemember. The O-ring has a substantially round cross-section.

It is readily seen that as the male and female members are screwedtogether the contact rings are moved into contact with each other and asthey are joined, the angle causes a wedging action between the ringsthus providing a reliable electrical contact therebetween. The rings aresealingly separated from fluids inside and outside the drill string bythe sealingly mating shoulders and the O-ring seal. In addition to thesealing effects thereby achieved, the insulation which is positioned oneach side of the rings to insulate the rings from the members in whichthey are positioned tends to sealingly contact by a wedging action whenthe members are screwed together thus providing a further sealingaction. The combination of sealing effects thereby achieved results inan effective seal preventing the rings from contacting fluids inside oroutside the drill string.

Many variations in the placement of the sealing means are possible. Forinstance, in FIG. 2 the first sealing means 48 is shown as a generallyring-shaped substantially full-circle resilient member 56 in a groove 58positioned on the shoulder of the male member of the drill string pipe.The second sealing means is shown as an O-ring 52 in a groove 54positioned on the male member of the drill string pipe. The contactsurfaces 60 are more particularly shown.

In FIG. 3 a still further embodiment of the invention is shown whereinthe sealing means comprises sealingly mating shoulders 24 and 26 inconjunction with an O- "ber,

ring 62 positioned in a groove 64 on the female member.

In FIG. 4 the first sealing means comprises a generally ring-shapedsubstantially full-circle resilient member 66 positioned in a groove 68on the shoulder of the female member. The second sealing means comprisesan O-ring 62 positioned in a groove 64 on the female member.

In FIG. 5 a further embodiment of the present invention is shown whereinthe first sealing means comprises an O-ring 56 positioned in a groove 58on the male member. The second sealing means comprises a generallyring-shaped substantially full-circle resilient member 62 positioned ina groove 64 on the female mem- In FIG. 6 a is shown wherein the firstsealing means comprises an O-ring 66 positioned in a groove 68 on thefemale member. The second sealing means comprises an O- ring 52positioned in a groove 54 on the male member.

The O-rings are of any suitable configuration known to those skilled inthe art and are desirably fabricated of a suitable resilient materialwhich is resistant to the temperatures and chemical environmentsencountered in drilling operations. Such O-rings are well-known to thoseskilled in the art and are commercially available. Desirably the O-ringmay be of an other than round configuration as shown in FIGS. 2, 4 and 5so that it is more readily retained in positions wherein the resilienceof the O-ring is insufficient to retain the O-ring in position as forinstance O-ring 56 in FIG. 2. In the embodiment shown in FIG. 1 it willbe noted that the resilience of the O-ring tends to hold it in positionin the groove between the ring and the threads on the male member.

The embodiment shown in FIG. 1 is a particularly desired embodimentsince the shoulders are readily machined to tolerances such that thejunction of the drill pipe sections results in a sealing junction. It ismuch less difficult to achieve a sealing junction of such shoulders whenonly one such junction is attempted; in other words, no attempt is madeto machine the remaining sections of the drill pipe members to atolerance such that other metal-to-metal seals are achieved. It isreadily seen that in the embodiment shown in FIG. 1 the O-ring ispositioned in an area where it is extremely unlikely that it will bedamaged by oil field handling and the like. The rings 30 and 32 are alsopositioned in positions which are not susceptible to damage during oilfield handling and the like. The ring positioned in the female member isdesirably positioned as shown since it is somewhat protected by theshoulder of the female section. The ring positioned in the femalesection may be positioned in a cavity as shown in FIG. 1 or in a groove70 as shown in FIG. 2. Such variations are within the scope of thepresent invention and many such variations and modifications arepossible within the scope of the present invention. The remainingembodiments shown are desirable; however, for a variety of reasons theembodiment discussed above is prefered.

It is noted that the O-ring positioned on the male member between thering and the threads is much more readily retained in position prior tomake-up of the joint than are O-rings positioned on the shoulders of themale and female members or the O-rings positioned between the ring andthe threads on the female member. In such embodiments it is desirable touse O-rings still further embodiment of the invention or the like shapedto be retained in a groove. cavity or the like. It is readily seen thatthe resilience of the O- ring 52 alone retains it in position in theembodiments shown in FIG. 1 and FIG. 2.

The sealing means may be formed of suitable resilient materials such asrubbers, silicon rubbers. silicon rubber resins. plastics and the likeas is well-known to those skilled in the art.

The insulation may be any suitable insulating mate rial such as rubbers.silicon rubber-like resins. plastics fiberglass filled rubbers.resilient reinforced plastics. fiberglass reinforced plastics and thelike. Desirably the insulation used to insulate the ring positioned inthe male member therefrom is more resilient than the insulating materialused to insulate the ring positioned in the female member therefrom. Itis desirable that the insulation positioned in the female member be lessresilient since it is more likely that this ring and the insulatingmaterial in which it is positioned will be subjected to contact withother objects during handling as it is somewhat more exposed than is thering positioned in the male member and accordingly it is desirable thatthis insulation be more rigid and damage resistant.

The contact surfaces of the rings tend to wedge together upon screwingthe male and female members together thus insuring a good electricalcontact between the rings. The wedging action tends to cause the contactsurfaces to mate with more force than a nonwedging action and tends toover-come the possibility of small particulate matter being lodgedbetween the rings. preventing electrical contact and the like.Desirably, the angle 6 formed with the longitudinal axis of the drillpipe by the contact surfaces is from about to about 60. Preferably, theangle is from about to about 55. The contact rings are fabricated fromany suitable electrically conductive material. Particularly preferredmaterials are copper. brass and the like.

As will be obvious to those skilled in the art a plurality of suchjoints is required to join a pluarlity of drill string pipe sectionstogether to form a telemetering drill string suitable for drilling tovarious depths. The insulated electrical conductor is positioned in thedrill string pipe by affixing it to the inner diameter of the pipe withadhesives, positioning it in a plastic lining inside the drill pipe,positioning it between the walls of double-walled drill pipe and thelike. Many such methods are known to those skilled in the art and neednot be discussed further since such variations are suitable for use inconjunction with the improvement of the present invention.

Having thus described the invention, it is pointed out that theforegoing descrition of preferred embodiments is illustrative ratherthan limiting in nature and that many variations and modifications arepossible within the scope of the present invention. In fact, it isanticipated that many such variations and modifications may appearobvious and desirable to those skilled in the art upon a review of theforegoing description of preferred embodiments.

Having thus described the invention, 1 claim:

1. In a telemetering drill string in which segments of an insulatedelectrical conductor are joined by electrical connectors in matingportions of drill string pipe joints that contain mating shoulders, animprovement in the arrangement of electrical connectors comprising:

a. in each drill string pipe joint, said joints comprising the union ofamale and a female threaded member,

positioning in each of said joints a first and a second ring-shapedsubstantially fullcircle contactmaking ring, said first ring beingpositioned in said male member in a groove between said shoulder and thethreaded portion of said member. said second ring being positioned insaid female member in a cavity between said shoulder and the threadedportion of said member. each of said rings being in electrical contactwith a segment of said insulated electrical conductor. electricallyinsulated from the member in which it is positioned and having a contactsurface forming an angle from 15 to 65 with the longitudinal axis ofsaid drill string;

b. a first and second sealing, means positioned in each drill stringpipe joint to sealingly separate said rings from fluids inside andoutside said drill string. said first sealing means being positionedbetween said rings and the outer diameter of said drill string pipe andsaid second sealing means being positioned between said rings and thethreaded portion of said joint; and,

c. resilient biasing means operatively associated with at least one ofsaid rings to urge said ring toward a position from which it isdisplaced by the adjacent contact-making ring as the members are screwedtogether.

2. The improvement ofclaim I wherein said angle is from 40 to 55.

3. The improvement of claim 1 wherein said first sealing means consistsof sealingly mating shoulders and said second sealing means is agenerally ringshaped substantially full-circle resilient sealing member.

4. The improvement of claim 3 wherein said sealing member has asubstantially round cross-section and is positioned in a groove on saidmale member.

5. The improvement of claim 3 wherein said sealing member is positionedin a groove on said female member.

6. The improvement of claim 1 wherein said first sealing means consistsof a generally ring-shaped substantially full-circle resilient sealingmember positioned in a groove on said male member and said secondsealing means consists of a generally ring-shaped, substantiallyfull-circle resilient member positioned in a groove on said male member.

7. The improvement of claim 1 wherein said first sealing means consistsof a generally ring-shaped substantially full-circle resilient sealingmember positioned in a groove on said male member and said secondsealing means consists of a generally ring-shaped, substantiallyfullcircle resilient member positioned in a groove on said femalemember.

8. The improvement of claim 1 wherein said first sealing means consistsof a generally ring-shaped, sub stantially full-circle resilient sealingmember positioned in a groove in said female member and wherein saidsecond sealing means comprises a generally ringshaped, substantiallyfull circle resilient sealing member positioned in a groove on said malemember.

9. The improvement of claim 1 wherein said first sealing means consistsof a generally ring-shaped, substantially full-circle resilient sealingmember positioned in a groove in said female member and wherein saidsecond sealing means comprises a generally ringshaped, substantiallyfull circle resilient sealing member positioned in a groove on saidfemale member.

10. The improvement of claim 1 wherein said insulating material used toinsulate the ring on said male member therefrom is more resilient thanthe insulation used to insulate the ring on said female membertherefrom. =i l l =l=

1. In a telemetering drill string in which segments of an insulatedelectrical conductor are joined by electrical connectors in matingportions of drill string pipe joints that contain mating shoulders, animprovement in the arrangement of electrical connectors comprising: a.in each drill string pipe joint, said joints comprising the union of amale and a female threaded member, positioning in each of said joints afirst and a second ring-shaped substantially full-circle contact-makingring, said first ring being positioned in said male member in a groovebetween said shoulder and the threaded portion of said member, saidsecond ring being positioned in said female member in a cavity betweensaid shoulder and the threaded portion of said member, each of saidrings being in electrical contact with a segment of said insulatedelectrical conductor, electrically insulated from the member in which itis positioned and having a contact surface forming an angle from 15* to65* with the longitudinal axis of said drill string; b. a first andsecond sealing means positioned in each drill string pipe joint tosealingly separate said rings from fluids inside and outside said drillstring, said first sealing means being positioned between said rings andthe outer diameter of said drill string pipe and said second sealingmeans being positioned between said rings and the threaded portion ofsaid joint; and, c. resilient biasing means operatively associated withat least one of said rings to urge said ring toward a position fromwhich it is displaced by the adjacent contact-making ring as the membersare screwed together.
 1. In a telemetering drill string in whichsegments of an insulated electrical conductor are joined by electricalconnectors in mating portions of drill string pipe joints that containmating shoulders, an improvement in the arrangement of electricalconnectors comprising: a. in each drill string pipe joint, said jointscomprising the union of a male and a female threaded member, positioningin each of said joints a first and a second ring-shaped substantiallyfull-circle contact-making ring, said first ring being positioned insaid male member in a groove between said shoulder and the threadedportion of said member, said second ring being positioned in said femalemember in a cavity between said shoulder and the threaded portion ofsaid member, each of said rings being in electrical contact with asegment of said insulated electrical conductor, electrically insulatedfrom the member in which it is positioned and having a contact surfaceforming an angle from 15* to 65* with the longitudinal axis of saiddrill string; b. a first and second sealing means positioned in eachdrill string pipe joint to sealingly separate said rings from fluidsinside and outside said drill string, said first sealing means beingpositioned between said rings and the outer diameter of said drillstring pipe and said second sealing means being positioned between saidrings and the threaded portion of said joint; and, c. resilient biasingmeans operatively associated with at least one of said rings to urgesaid ring toward a position from which it is displaced by the adjacentcontact-making ring as the members are screwed together.
 2. Theimprovement of claim 1 wherein said angle is from 40* to 55*.
 3. Theimprovement of claim 1 wherein said first sealing means consists ofsealingly mating shoulders and saiD second sealing means is a generallyring-shaped substantially full-circle resilient sealing member.
 4. Theimprovement of claim 3 wherein said sealing member has a substantiallyround cross-section and is positioned in a groove on said male member.5. The improvement of claim 3 wherein said sealing member is positionedin a groove on said female member.
 6. The improvement of claim 1 whereinsaid first sealing means consists of a generally ring-shapedsubstantially full-circle resilient sealing member positioned in agroove on said male member and said second sealing means consists of agenerally ring-shaped, substantially full-circle resilient memberpositioned in a groove on said male member.
 7. The improvement of claim1 wherein said first sealing means consists of a generally ring-shapedsubstantially full-circle resilient sealing member positioned in agroove on said male member and said second sealing means consists of agenerally ring-shaped, substantially full-circle resilient memberpositioned in a groove on said female member.
 8. The improvement ofclaim 1 wherein said first sealing means consists of a generallyring-shaped, substantially full-circle resilient sealing memberpositioned in a groove in said female member and wherein said secondsealing means comprises a generally ring-shaped, substantially fullcircle resilient sealing member positioned in a groove on said malemember.
 9. The improvement of claim 1 wherein said first sealing meansconsists of a generally ring-shaped, substantially full-circle resilientsealing member positioned in a groove in said female member and whereinsaid second sealing means comprises a generally ring-shaped,substantially full circle resilient sealing member positioned in agroove on said female member.